docs: def bbox(self):
          """
          The bounding box ``(ymin, xmin, ymax, xmax)`` of the minimal
          rectangular region containing the source segment.
          """
  
          # (stop - 1) to return the max pixel location, not the slice index
          return (self._slice[0].start, self._slice[1].start,
                  self._slice[0].stop - 1, self._slice[1].stop - 1) * u.pix